Two experiments are proposed that investigate the development of interest in activities. The specific hypotheses are that: (a) treatment methods that provide valid information about capabilities promote interest more than methods providing less explicit capability information, and (b) Increases in perceptions of competence for an activity predict the development of interest in that activity. Subjects will be 70 children identified as low arithmetic achievers. Prior to treatment, children's perceptions of competence, skill, and interest in subtraction will be assessed. Children then will be randomly assigned (within sex) to N equals 10 conditions. Treatments will be administered over three, 40 minute session, during which children will work individually on a packet of subtraction materials that provides instruction and practice problems. In Experiment 1 (3 conditions), children will be contingently rewarded for progress on the packet, noncontingently rewarded for participation in the experiment, or not rewarded. In Experiment 2 (4 conditions), the experimenter will suggest to half of the children a specific goal of completing a minimum number of pages each session; the other half the experimenter will suggest the general goal of working one's best. Half of the children in each of these groups will also receive progress-contingent rewards, while the other half will receive no reward. Following treatment, children's perceptions of competence, skill, and interest in subtraction will be reassessed, and a delayed interest test will be given 2 weeks later. Analysis of variance and multiple regression procedures will be used to determine intergroup differences and whether perceptions of competence reliably predict interest. It is predicted that both specific goals and progress-contingent rewards will promote interest because they provide explicit information concerning performance capabilities. It is further predicted that perceptions of competence will account for a reliable portions of explained variability in children's interest in subtraction. The links to current theory and research are discussed.